Two people, including the owner of a luxury house under construction, were injured when its facade collapsed in Muang district of Samut Sakhon on Saturday afternoon.
The front portion of the three-storey building in Soi Wat Sri Muang in tambon Tha Sai collapsed at about 2pm, said Pol Maj Pandecha Manalert, the duty officer at the Muang district police station.
Police and rescue workers rushed to the scene and found two people trapped in the wreckage of the collapsed section.
The injured were identified as Boonmak Lun-ubon, 51, and his son Chanont, 26. Mr Boonmak was seriously injured, while his son sustained injuries to his right leg. They were taken to a nearby hospital, Thai media reported on Saturday.
Jeerasak Jiraprayut, 50, a contractor from Thung Khru district in Bangkok, told police that he had been hired by Mr Boonmak to build his 20-million-baht house. Construction began about six months ago.
While 20 workers were pouring concrete on the third floor, the front section started to shake, said Mr Jeerasak. He went to inspect the area immediately and shortly afterward the concrete started to crumble, forcing workers to flee in panic.
Mr Boonmak and his son were inspecting the construction at the site at the time.
Police are continuing their investigation.